Serum levels of soluble urokinase plasminogen activator receptor as a new inflammatory marker in adolescent obesity

Soluble urokinase plasminogen activator receptor (suPAR) in children with obesity or type 1 diabetes as a marker of endothelial dysfunction: a cross-sectional study

Pediatric obesity and type 1 diabetes mellitus (T1DM) represent two common chronic diseases associated with chronic inflammation, endothelial dysfunction and long-term complications. The aim of the present study was to assess the possible diagnostic and prognostic value of soluble urokinase plasminogen activator receptor (suPAR), a marker of inflammation and impaired endothelial function, in children with the diseases. In this cross-sectional study, children and adolescents with T1DM (N = 41) or obesity (N = 37), aged < 18 years old, and without proteinuria were included, together with children of similar age and without evident morbidity that served as controls (N = 42). Serum samples were obtained during standard outpatient follow up and the urokinase-type plasminogen activator receptor (suPAR) concentrations were measured using a commercially available sandwich ELISA kit (DUP00, R&D systems). Clinical and biochemical indices that were also assessed include body mass index (BMI) z-score, Tanner stages, glycosylated haemoglobin (HbA1c), fasting lipid profile and serum creatinine. Mean serum suPAR levels were significantly higher in patients with obesity compared to patients with T1DM and controls, while children with T1DM had similar suPAR levels to controls. Also, serum suPAR levels showed a negative correlation with age (Spearman rho -0.359, p < 0.001) and serum creatinine levels (Spearman rho -0.334, p = 0.005), and a positive correlation with BMI z-score (Spearman rho 0.354, p = 0.009) in the whole cohort.  Conclusion: Serum suPAR may be a useful predictive marker of inflammation or endothelial dysfunction for children with obesity and T1DM, as well as a promising therapeutic target. Further studies are needed in order to clarify whether the reported differences in suPAR levels could reflect a greater impairment of the inflammation status and endothelial function in children with obesity compared to children with T1DM. What is Known: • Paediatric obesity and type 1 diabetes are characterised by chronic inflammation and metabolic dysregulation. • Urokinase plasminogen activator receptor (uPAR) has been proposed as a useful biomarker for chronic inflammation and cardiovascular risk in adults. What is New: • Serum suPAR levels were increased in children and adolescents with obesity compared to those with T1DM and healthy controls; thus, obesity may affect the inflammatory status and endothelial function to a higher degree than T1DM during childhood. • Serum suPAR may serve as a diagnostic and predictive marker of inflammation and endothelial dysfunction for children and adolescents with obesity and T1DM.

Plasma levels of soluble urokinase plasminogen activator receptor (suPAR) and high-sensitivity C-reactive protein after Roux-en-Y gastric bypass or sleeve gastrectomy: a 1-year prospective observational study

PURPOSE

Low-grade inflammation in obesity contributes to the development of cardiovascular disease, diabetes mellitus and cancer, and is associated with increased mortality. The purpose of this 1-year prospective observational study was to examine the weight loss effect of bariatric surgery on plasma concentrations of two inflammatory markers, namely high-sensitivity C-reactive protein (hsCRP) and soluble urokinase-type plasminogen activator receptor (suPAR), in patients with obesity.

METHODS

Sixteen subjects without obesity and 32 patients with obesity class III, who had already settled upon Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) were included in the study. Subjects without obesity were examined once, at baseline; patients with obesity were examined preoperatively (baseline) and 3, 6 and 12 months postoperatively.

RESULTS

Plasma suPAR and hsCRP concentrations at baseline were higher in patients with obesity than in lean participants (2.68 ± 0.86 vs 1.86 ± 0.34 ng/mL, p < 0.001 and 9.83 ± 9.55 vs 1.36 ± 1.95 mg/dL, p < 0.001). Levels of suPAR following bariatric surgery increased significantly 3 months after either RYGB or SG (3.58 ± 1.58 vs 3.26 ± 0.7 ng/mL, respectively) and declined at 6 (3.19 ± 1.75 vs 2.8 ± 0.84 ng/mL, respectively) and 12 months (2.6 ± 1.5 vs 2.22 ± 0.49 ng/mL, respectively; p < 0.05 for the effect of time on suPAR levels during the study), whereas those of hsCRP declined consistently after bariatric surgery (3 months: 5.44 ± 3.99 vs 9.47 ± 11.98 mg/dL, respectively; 6 months; 5.39 ± 5.6 vs 10.25 ± 17.22 mg/dL, respectively; and 12 months: 2.23 ± 2.5 vs 3.07 ± 3.63 mg/dL, respectively; p < 0.001 for the effect of time on hsCRP levels during the study). 1-year change in BMI was negatively associated with suPAR levels at 12 months.

CONCLUSION

Our findings support an association between obesity and low-grade inflammation. Weight loss following bariatric surgery is associated with a consistent decline in plasma hsCRP, while plasma suPAR levels increase at 3 months and decline by 12 months.

Serum soluble urokinase plasminogen activator receptor in adolescents: interaction of chronic pain and obesity

Pediatric chronic pain is exacerbated by obesity. Serum soluble urokinase plasminogen activator receptor, a novel inflammation biomarker, was increased in obese adolescents with chronic pain indicating interactive inflammatory conditions.

Introduction:

Obesity in adolescents is increasing in frequency and is associated with short-term and long-term negative consequences that include the exacerbation of co-occurring chronic pain.

Objective:

To determine whether the interaction between chronic pain and obesity would be reflected in changes in serum soluble urokinase plasminogen activator receptor (suPAR) concentrations, a novel marker of systemic inflammation associated with obesity, insulin resistance, and cardiovascular disease.

Methods:

We measured serum suPAR levels in 146 adolescent males and females with no pain or obesity (healthy controls; n = 40), chronic pain with healthy weight (n = 37), obesity alone (n = 41), and the combination of chronic pain and obesity (n = 28).

Results:

Serum suPAR (median [interquartile range]) was not increased by chronic pain alone (2.2 [1.8–2.4] ng/mL) or obesity alone (2.2 [2.0–2.4] ng/mL) but was increased significantly with the combination of chronic pain and obesity (2.4 [2.1–2.7] ng/mL; P < 0.019). This finding confirms the proposition that pain and obesity are inflammatory states that display a classic augmenting interaction.

Conclusion:

We propose that measurement of serum suPAR can be added to the armamentarium of serum biomarkers useful in the evaluation of mechanisms of inflammation in adolescent obesity and chronic pain.

Sex Differences in Circulating Soluble Urokinase-Type Plasminogen Activator Receptor (suPAR) Levels and Adverse Outcomes in Coronary Artery Disease

Background

Women have higher circulating levels of soluble urokinase‐type plasminogen activator receptor (suPAR), and elevated suPAR is associated with cardiovascular risk. The independent association of sex with suPAR and the impact of sex on its association with cardiovascular risk are unknown.

Methods and Results

Plasma suPAR was measured using ELISA in 2 cohorts of 666 asymptomatic individuals (49 years, 65% women) and 4184 patients with coronary artery disease (63 years, 37% women). Independent association of sex with suPAR was studied using linear regression models adjusted for demographics, risk factors, and visceral adiposity in asymptomatic participants. Impact of sex on association of suPAR with all‐cause mortality was studied in patients with coronary artery disease using multivariable‐adjusted Cox models. Sex‐specific suPAR cutoffs for predicting all‐cause mortality were calculated. Asymptomatic women had 10% higher suPAR compared with men after adjusting for confounders, and visceral adiposity partly accounted for this association. Over a median follow‐up of 5.2 years, 795 deaths were recorded in patients with coronary artery disease. Log₂‐transformed suPAR was independently associated with mortality (hazard ratio per 1‐SD 1.72, 95% CI 1.60–1.85) and an interaction with sex was noted (P=0.005). Association of suPAR with mortality was slightly weaker in women (hazard ratio 1.61, 95% CI 1.41–1.83) compared with men (hazard ratio 1.83, 95% CI 1.67–2.00). However, using sex‐specific suPAR cut‐offs (4392 pg/mL for women and 3187 pg/mL for men), a similar mortality incidence was observed for both sexes (38.5% and 35.5%, respectively, P=0.3).

Conclusions

Women have 10% higher plasma suPAR levels compared with men. Elevated sex‐specific plasma suPAR levels are equally predictive of risk of adverse events in both sexes.

Pregestational overweight and obesity are associated with differences in gut microbiota composition and systemic inflammation in the third trimester

The obesity epidemic is a global challenge, and the velocity of propagation is high in the population at reproductive age. Overweight and obesity during pregnancy have been associated with high birth weight and an increased risk of childhood obesity, reinforcing the risk of other non-communicable diseases. Obesity involves chronic low-grade systemic inflammation. New biomarkers for early detection of obesity risk are urgently required. The aim of this study was to identify the connection between pregestational BMI (pre-BMI) status and inflammatory biomarkers during the third trimester of pregnancy and their association with intestinal microbiota composition. Fifty-four pregnant women were classified according to pre-pregnancy BMI as normoweight, overweight, or obese. Weight gain, inflammatory biomarkers (hs_CRP, haptoglobin, and suPAR), and microbiota composition were assessed during the third trimester. A significant lower weight gain for obese mothers and a positive correlation between pre-BMI and inflammatory biomarkers were detected (Spearman’s correlation). Haptoglobin levels were significantly higher in overweight and obese mothers. Higher Firmicutes levels and a higher ratio Firmicutes/Bacteroidetes were observed in the overweight and obese subjects. High hs_CRP and haptoglobin levels were also correlated with decreased microbiota diversity (Shannon index), whereas haptoglobin and hs_CRP values were correlated with several microbiota components, such as Ruminococcus gnavus and Faecalibacterium, and with specific phyla in the normoweight and overweight mothers; no significant associations with microbiota were found for suPAR. In conclusion, haptoglobin and hs_CRP reflected pregestational BMI status and related microbiota components, but haptoglobin was a better biomarker for microbiota associated with overweight. suPAR was associated with low grade inflammation dependent on pre-pregnancy BMI, but it was not related to deviated microbiota profiles.